go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/server/dsmapper/utils.go (about)

     1  // Copyright 2018 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package dsmapper
    16  
    17  import (
    18  	"context"
    19  
    20  	"go.chromium.org/luci/common/logging"
    21  	"go.chromium.org/luci/common/retry/transient"
    22  	"go.chromium.org/luci/gae/service/datastore"
    23  
    24  	"go.chromium.org/luci/server/dsmapper/dsmapperpb"
    25  )
    26  
    27  // runTxn runs a datastore transaction retrying the body on transient errors or
    28  // when encountering a commit conflict.
    29  func runTxn(ctx context.Context, cb func(context.Context) error) error {
    30  	var attempt int
    31  	var innerErr error
    32  
    33  	err := datastore.RunInTransaction(ctx, func(ctx context.Context) error {
    34  		attempt++
    35  		if attempt != 1 {
    36  			if innerErr != nil {
    37  				logging.Warningf(ctx, "Retrying the transaction after the error: %s", innerErr)
    38  			} else {
    39  				logging.Warningf(ctx, "Retrying the transaction: failed to commit")
    40  			}
    41  		}
    42  		innerErr = cb(ctx)
    43  		if transient.Tag.In(innerErr) {
    44  			return datastore.ErrConcurrentTransaction // causes a retry
    45  		}
    46  		return innerErr
    47  	}, nil)
    48  
    49  	if err != nil {
    50  		logging.WithError(err).Errorf(ctx, "Transaction failed")
    51  		if innerErr != nil {
    52  			return innerErr
    53  		}
    54  		// Here it can only be a commit error (i.e. produced by RunInTransaction
    55  		// itself, not by its callback). We treat them as transient.
    56  		return transient.Tag.Apply(err)
    57  	}
    58  
    59  	return nil
    60  }
    61  
    62  func isFinalState(s dsmapperpb.State) bool {
    63  	return s == dsmapperpb.State_SUCCESS || s == dsmapperpb.State_FAIL || s == dsmapperpb.State_ABORTED
    64  }